Various forms of couplings are utilized for connecting high pressure hose to items, such as a pressure washer and dispensing gun, in high pressure hydraulic systems. In such systems, it is important that the couplings enable sealed connection between the hose and the pressure washer or spray gun for safe and reliable operation. From an economic and convenience standpoint, particularly in consumer operated pressure washer products, it is desirable that the hose couplings also permit use with various sized inlet and outlet fittings of the pressure washer and spray guns with which the hose is used. U.S. Pat. No. 6,779,745, assigned to the same assignee as the present application, the disclosure of which is incorporated herein by reference, discloses a high pressure hose with couplings adapted for versatile usage with different sized inlet and outlet fittings.
It is not only necessary that the couplings permit reliable safe connection of the hose to the pressure washer or spray gun, but that they enable safe uncoupling and disconnection of the hose in such systems, which can remain substantially pressurized following usage. For example, in pressure washer systems, following use of the pressure washer, it is common for pressure within the hose downstream of the pressure washer to remain at several thousand psi. Hence, uncoupling of the hose from the pressure washer under such conditions can create a danger to the user by virtue of sudden high pressure discharge from the coupling upon disconnection.